The anchoring of a charter sailboat

If we rent a sailboat without skipper, one of the things that we should review urgently before starting our voyage will be the anchoring.

Regardless of the type of anchor that the boat carries, its chain, lifting and mooring system, the whole structure should be well maintained, neat and clear. We must not forget that the anchoring, as well as allowing us to spend pleasant hours bathing and relaxing in a bay, can also be the last resort there is left on board when everything else fails and the coast is close. When renting a sailboat, as well as checking many other things, we must submit all the anchoring system to a performance review which includes the state of its joints and the security state of all its component parts.

The anchor well

It should be clear and clean, should have a lid and, of course, a good drainage scupper which must always be clean and constantly drain the water which rises with the chain, which enters through its lid or that we pour after each anchoring when rinsing it with fresh water from a hose. Algae, silt, sand or mud coming up with the anchor chain after anchoring can easily clog the drain, causing water to stay longer than desired or not to drain at all, with the consequent deterioration of the well and its interior protection. A fortiori, if our anchor windlass is in the well or under the cap, we take care of this aspect so that moisture caused by accumulated water does not affect its electrical components even if they are very well protected.

We will thoroughly check the joint of the chain with a rope to the eyebolt connected with the bulkhead of the well. This rope will secure the anchor in case the entire chain is released. Moreover, if there is an emergency and the anchor gets stuck or the windlass fails us and we cannot raise the anchor by hand, then we simply cut the rope to get rid of the whole set. If we have to go this far, tying a fender to the end of the chain can help us recover the whole abandoned anchor later on, without endangering the ship and all its crew.

The windlass

Nowadays, almost all charter boats, whether sail or motor, are equipped with an electric anchor windlass to make this maneuver more comfortable and to prevent hand, kidney and back injuries during each anchoring. An essential precaution that we take before each anchoring is to have the engine (or engines) running. Electric windlasses, because of the hard work made each time they have to raise or lower the anchor, consume much power and overload the battery, leaving us with an empty one so we cannot start the engine when ready to sail. However, currently, most ships, either sailing or motor, incorporate a safety system that does not allow us to use the windlass if the engine is not running. If the windlass is equipped with a wired remote control, it must be in a safe dry place, to ensure that it will always be in a working state. Its outer plug must remain strongly covered up and protected from water to prevent the contacts from oxidizing. Finally, the deck buttons should also have their rubber covers in good condition.

The chain

The following table can help us have a very rough idea of ​​the size and the minimum amount of chain that should be taken on board depending on the boat.

Approximate reference table:

Ship displacement

Minimum anchor weight

Shackle diameter

Chain diameter

Rope diameter

800 kg

6 kg

8 mm

6 mm

10 mm

1.000 kg

8 kg

8 mm

6-7 mm

10 mm

2.000 kg

10 kg

10 mm

8 mm

14 mm

3.000 kg

12 kg

10 mm

8 mm

14 mm

4.500 kg

14 kg

10 mm

10 mm

14 mm

8.000 kg

16 kg

12 mm

10 mm

18 mm

12.000 kg

20 kg

12 mm

10 mm

18 mm

16.000 kg

24 kg

16 mm

12 mm

22 mm

20.000 kg

34 kg

16 mm

14 mm

24 mm

30.000 kg

40 kg

16 mm

14 mm

24 mm

+ 30.000 kg

60 kg

18 mm

16 mm

28 mm

At present all the chains are usually galvanized and imperatively must be calibrated if they pass by an electric windlass.

The shackles

The shackle connecting the anchor to the chain should be well calculated, depending on the diameter of the chain and the tonnage of the ship (See table above). If its diameter is lower than the chain’s one (careful with stainless steel, its resistance is different from that of steel), this will be the anchoring’s weak point and could break if the force is excessive. In addition to its proper size and diameter, it must be well tightened and one should ensure its closure with an effective system. A steel wire, stainless or galvanized, secured through the eye of the pin and to the shackle will prevent us from losing the anchor as the shackle will not unscrew. There are also shackles which pin must be screwed with a screwdriver. This way, they are prevented from unscrewing.

The swivel

Installed between the anchor and the chain’s shackle, it must be of good size and quality, it is a key part of our mooring, especially if the boat we’ve rented is over 35 feet. Swivels are usually calculated with a real breaking load for coupling to a given chain and a certain tonnage of the ship. Its function is to prevent the chain from swiveling and from hindering the good grip of the anchor.

Finally some practical advice if we are not very familiar with mooring:

The length of the chain must be at least 5 times longer than the boat’s length.

The anchoring rope will preferably be polyamide, for its resistance to breakage and friction and also because it has high elasticity acting as a damper. (A polyamide rope after stretching can reach more than 20% of its length).

Consider depth and wind strength to determine the length of the anchor line:

Up to strength 3: minimum of 3 times the depth

Up to strength 6: minimum of 5 times the depth

Up to strength 9: minimum of 7 times the depth. From strength 5/6, it is not wise to anchor, better withstand the storm at sea.